This cache is located at Springwell Lock and can be accessed either from the very close by parking or a nice stroll down from the Aquadrome or if you are doing them all in this series in order, you'll be getting tired by now!
If you've come via the Aquadrome, you'll have passed the Hanging Monkey, this is actually marked on Google Maps as a landmark. It's actually at the derelict Harefield Limeworks which I've not been able to find much history about.
Other than being a beutiful spot along the canal for a picnic, (which may be ruined by the odd large lorry that somehow gets over the tiny bridge), the most famous thing about Springwell is that it was a location for a scene in Dr Who.
You are looking for a magnetic nano cache. Please replace carefully. Bring your own pen